Depends where you are. DP went to Turkey last year for a climbing trip and there were NO food shops much to his surprise, the only shop was a sort of newsagent where you could buy biscuits and sweets. But the places to eat were very cheap and the food was fantastic.
I think it will depend on which part of Turkey I'd imagine, I have been to Hisaronou/Olu Deniz and it would be very easy to self cater there, there were some great little supermarkets and even an 'Azda'
we cant afford to eat out ( or really want to tbh) for 14nights. Have fridge freezer, 4 rings. I think I read on trip advisor there is a Lidl or similar within walking distance.
Have any of you happily self catered? WE went to Turkey several times pre kids, but all i can remember is how NICE the food was. WIth kids we want crusty bread and ham for lunches and milk that they wont regard as weird for breakfasts.